Compare Concrete5 vs. Cosmic.js
Concrete 5 is a long running content management system. It is known for it's user friendly interface and with it's recent iterations has moved to adopt Symfony components.
Cosmic.js is a CaaS based on GraphQL. It follows on the footsteps of both Contentful and GraphCMS.
CMSes vailable for comparison: BackBee, Bolt CMS, Concrete5, Contenta, Contentful, Cosmic.js, Craft CMS, Drupal 8, eZ Platform, Fork CMS, GraphCMS, Grav, Jarves, Joomla!, Kunstmaan, October CMS, Open Orchestra, Pagekit, Pimcore, PyroCMS 3, Reservoir, Spress, Sulu CMS, Symfony CMF, Symphony CMS